Despite the clinical and public health significance of alcohol use disorders, relatively little is known about the childhood risk factors that precede alcohol problems. This implies that future studies must adopt a more developmentally-informed approach to the study of the timing (i.e., onset), sequencing, and progression from initial alcohol expectancies to alcohol use initiation, and to alcohol problems. Using a rigorously characterized sample of ethnically- and socioeconomically-diverse 200-225 6-9 year-old children with and without attention- deficit/hyperactivity disorder (ADHD), the proposed study aims to conduct a two-year prospective longitudinal study to understand the behavioral, neuropsychological, and family predictors of early alcohol expectancies and alcohol engagement. At baseline, children and families were comprehensively assessed using a mixture of multiple methods (i.e., rating scales, structured and semi-structured interviews, analogue, observational) and informants (i.e., parent, interviewer, teacher) across cognitive, academic, neuropsychological, family, and psychopathology domains. The proposed follow-up will preserve similar methods/constructs as baseline, with appropriate developmental modifications, to facilitate cross-time comparisons. However, the focus of the prospective follow-up is to incorporate rigorous and developmentally-sensitive assessments of alcohol-related phenotypes in children and parents. Our long-term goal is to leverage this large cross-sectional study of children with and without ADHD into a highly-informative prospective longitudinal study of the behavioral, neuropsychological, and family precursors of alcohol use disorders and related problems. Based on the premise that innovations in intervention and prevention can be expected from studies that identify potential causal risk factors for alcohol expectancies, use initiation, and escalation of alcohol use, we anticipate that findings from this study will help to reduce the considerable clinical and public health burden associated with alcohol use disorders. PUBLIC HEALTH RELEVANCE: To date, there are relatively few studies that have identified childhood precursors of alcohol expectancies and explicit use. The proposed study will help elucidate the behavioral, neuropsychological, and family determinants of alcohol expectancies and use in school-aged children. This study will also position the investigative team to follow this well-characterized sample into early adolescence and to characterize the timing and sequencing of alcohol use initiation and escalation.